In the second installment of her Marlborough Gardens Quartet, Bayer amply provides the dramatic tension and the compelling air of mystery that City of Childhood largely lacked. Continuing the saga of the Forsters, a 19th-century London banking family that harbors many dark secrets, she again uses her characters' putative diaries and journals, augmented by footnotes from the 20th-century ``caretakers'' of the Forster estate. Bayer here focuses on the downfall of brutal, greedy, manipulative Elijah Forster, as the outwardly respectable Nicholas Reston, in fact a master criminal, infiltrates the Forster clan. Meanwhile, Elijah's daughter Emma observes her father's sexual domination of her mother and his womanizing with members of the household, and herself becomes the victim of seduction. In this Victorian family, sexual relationships--variously overt and fantasied, secret and flaunted, marital, adulterous and perverted--always have less to do with love than with power. Bayer lingers over details of the dress and furnishings of the moneyed upper middle class, while also portraying the darker side of London life: drug addiction, prostitution, the degraded status of women, the poisonous slums of Newgate. Though her story sometimes carries too heavy a burden of intrigue and machinations, it acquires depth and persuasiveness that augur well for the remaining books in the series. (Oct.)